Maternal Cardiac and Respiratory Disease

Learning objectives

After completing this chapter, you should be able to distinguish physiologic pregnancy symptoms from cardiopulmonary warning signs; recognize peripartum cardiomyopathy, pulmonary edema, pulmonary hypertension, valvular disease, arrhythmia, pulmonary embolism, asthma, pneumonia, ARDS, and amniotic fluid embolism; apply pregnancy-specific oxygenation, hemodynamic, airway, and transport priorities; and select a destination matched to maternal and neonatal risk.

Opening transport scenario

A 30-year-old patient is six days postpartum and reports worsening orthopnea, chest pressure, and leg swelling. Heart rate is 122/min, BP 154/96 mm Hg, respiratory rate 30/min, and SpO₂ 90% on room air. She has bilateral crackles and cannot lie flat. She was told edema and fatigue were “normal after delivery.” The transport clinician must rapidly distinguish hypertensive pulmonary edema, peripartum cardiomyopathy, pulmonary embolism, pneumonia, and other causes while supporting oxygenation without worsening cardiac loading conditions.

1. Physiologic symptoms versus warning signs

Mild exertional dyspnea, a modest increase in heart rate, dependent edema, and a soft systolic flow murmur can occur in normal pregnancy. The following findings should not be dismissed as normal:

• Dyspnea at rest, progressive orthopnea, paroxysmal nocturnal dyspnea, or inability to speak normally.
• Persistent SpO₂ reduction, hemoptysis, cyanosis, pleuritic pain, or syncope.
• Chest pain, new sustained arrhythmia, exertional syncope, or marked resting tachycardia.
• Diastolic murmur, loud pathologic murmur, jugular venous distention, pulmonary crackles, or unilateral leg swelling.
• Severe hypertension with respiratory symptoms or new pulmonary edema.
• Sudden cardiovascular collapse during labor or shortly postpartum.

2. Structured cardiopulmonary assessment

3. Peripartum cardiomyopathy and heart failure

Peripartum cardiomyopathy is new systolic heart failure arising toward the end of pregnancy or in the months after delivery when no other cause explains the dysfunction. Symptoms often overlap with normal pregnancy, which contributes to delayed recognition. Echocardiography commonly demonstrates reduced left-ventricular systolic function.

Transport priorities

• Position upright or in the position that best supports ventilation; avoid supine compression during pregnancy.
• Use oxygen for hypoxemia and positive-pressure support when pulmonary edema or fatigue warrants it.
• Avoid reflexive large crystalloid boluses when congestion or pump failure is suspected.
• Continue ordered diuresis, vasodilator, inotrope, or vasopressor therapy with close BP and fetal assessment during pregnancy.
• Plan for dysrhythmia, cardiogenic shock, mechanical circulatory support, and a center with obstetric, cardiac, anesthesia, and neonatal capability.

Acute heart-failure medication selection depends on BP, congestion, pregnancy status, renal function, and cause. Some chronic heart-failure drugs are contraindicated during pregnancy but may become options postpartum; never extrapolate a nonpregnant regimen without specialist direction.

4. Hypertensive pulmonary edema

Severe preeclampsia can produce pulmonary edema through endothelial dysfunction, increased afterload, capillary leak, renal impairment, and iatrogenic fluid. Findings include severe hypertension, dyspnea, crackles, hypoxemia, and sometimes headache or neurologic symptoms. Treatment commonly combines oxygenation/ventilation support, BP reduction, seizure prevention when indicated, cautious fluid strategy, and diuresis under obstetric direction.

5. Valvular disease, congenital disease, and pulmonary hypertension

Pregnancy increases blood volume and cardiac output. Fixed obstructive lesions, severe regurgitation with ventricular dysfunction, cyanotic congenital disease, and pulmonary arterial hypertension can decompensate during gestation, labor, or postpartum volume shifts. Pulmonary hypertension carries particularly high maternal risk because the right ventricle may fail when pulmonary vascular resistance rises or systemic pressure falls.

• Avoid hypoxemia, hypercapnia, acidosis, pain, hypothermia, and excessive airway pressures in pulmonary hypertension.
• Prevent abrupt reductions in preload or systemic vascular resistance.
• Continue specialty pulmonary vasodilators without interruption.
• Use a Pregnancy Heart Team and transport to a center prepared for advanced cardiac and obstetric support.

6. Arrhythmias, acute coronary syndrome, and aortic disease

Palpitations are common, but sustained arrhythmia with hypotension, ischemia, heart failure, or altered mental status requires immediate treatment. Standard synchronized cardioversion and defibrillation energy are appropriate when indicated. Medication selection should account for pregnancy, underlying structure, QT interval, and specialist guidance.

Pregnancy and the postpartum period also increase the risk of spontaneous coronary artery dissection and aortic complications. Sudden severe chest or back pain, pulse or BP asymmetry, neurologic deficit, ischemic ECG changes, or shock requires rapid imaging and a destination with cardiovascular surgery or interventional capability.

7. Pulmonary embolism

Pregnancy is hypercoagulable, and risk remains elevated postpartum. PE may present with unexplained dyspnea, pleuritic pain, syncope, tachycardia, hypoxemia, hemoptysis, right-heart strain, or shock. Normal pregnancy symptoms can overlap, but persistent or sudden abnormalities require definitive evaluation.

• Do not withhold medically indicated imaging solely because the patient is pregnant.
• Use bedside ultrasound as an adjunct, not as a universal rule-out test.
• Continue ordered anticoagulation and verify dose, time, renal function, bleeding risk, and delivery plan.
• Massive PE with shock may require thrombolysis, catheter intervention, surgery, or extracorporeal support at an appropriate center.

8. Asthma, pneumonia, ARDS, and respiratory failure

Asthma

Undertreatment of maternal asthma can be more dangerous than appropriately selected medications. Treat bronchospasm promptly, correct hypoxemia, monitor fatigue and capnography, and recognize that a “quiet chest” may signal severe obstruction rather than improvement.

Pneumonia and ARDS

Pregnancy reduces oxygen reserve and can accelerate respiratory deterioration. Pneumonia, viral illness, aspiration, sepsis, and preeclampsia may progress to ARDS. Use lung-protective ventilation principles, adequate PEEP, and maternal oxygenation goals while avoiding extreme hypocapnia or permissive hypercapnia without specialist discussion.

Amniotic fluid embolism

AFE is a clinical syndrome of sudden hypoxemia, hypotension or arrest, and often coagulopathy during labor, birth, or the immediate postpartum period. There is no single confirmatory bedside test. Management is aggressive supportive resuscitation, hemorrhage treatment, and rapid multidisciplinary escalation.

9. Airway and ventilation

• Anticipate airway edema, aspiration risk, rapid desaturation, and difficult laryngoscopy.
• Preoxygenate in an optimized position and prepare suction, video laryngoscopy, smaller endotracheal tube, and backup airway.
• Use waveform capnography and interpret PaCO₂ in the pregnancy context; a value normal for a nonpregnant adult may represent relative hypoventilation.
• Avoid unnecessary high intrathoracic pressure in right-heart failure or pulmonary hypertension.
• Continue analgesia and sedation after intubation; maternal awareness and ventilator dyssynchrony are harmful.

10. Transport and destination planning

The 2025 ESC guideline emphasizes multidisciplinary cardiovascular care during pregnancy. Destination selection should match the likely need for obstetrics, cardiology, cardiac anesthesia, critical care, neonatal care, catheterization, cardiothoracic surgery, mechanical support, or ECMO.

11. Evolving case study

Phase 1: Initial support

The postpartum patient is placed upright, oxygen is initiated, ECG and capnography are applied, and IV access is confirmed. POCUS shows diffuse B-lines and reduced left-ventricular function without clear right-heart dilation.

Phase 2: Mechanism-directed treatment

The team avoids a routine fluid bolus, continues ordered diuretic and vasodilator therapy, and prepares noninvasive positive-pressure ventilation. The receiving center activates obstetric critical care and cardiology.

Phase 3: Deterioration

BP falls and perfusion worsens. The team reassesses for cardiogenic shock, medication effect, PE, hemorrhage, and sepsis, starts ordered vasoactive support, and diverts to the nearest center capable of advanced cardiac support.

12. High-yield chapter summary

1. Do not label progressive dyspnea, hypoxemia, chest pain, syncope, or orthopnea as normal pregnancy.
2. Peripartum cardiomyopathy often presents late in pregnancy or postpartum and requires echocardiography.
3. Pulmonary edema may be cardiogenic, hypertensive, renal, inflammatory, or iatrogenic.
4. Pulmonary hypertension requires meticulous avoidance of hypoxemia, hypercapnia, acidosis, and abrupt hemodynamic changes.
5. Pregnancy and postpartum status increase PE risk.
6. Asthma should be treated promptly; a silent chest is ominous.
7. AFE is a sudden clinical syndrome requiring supportive resuscitation and hemorrhage readiness.
8. The pregnant airway desaturates rapidly and may be edematous.
9. Do not reflexively give large fluid boluses to a congested patient.
10. Match destination to the likely need for obstetric and advanced cardiopulmonary rescue.

References

1. International Board of Specialty Certification. Maternal Fetal Transport Microcredential Candidate Handbook. Updated April 2026.
2. European Society of Cardiology. 2025 ESC Guidelines for the Management of Cardiovascular Disease and Pregnancy.
3. American Heart Association. Cardiovascular considerations in caring for pregnant patients.
4. Society for Maternal-Fetal Medicine. Guidance on maternal cardiac disease and pulmonary hypertension.
5. American College of Obstetricians and Gynecologists. Thromboembolism in pregnancy and postpartum care guidance.